modules/roles/files/mirror_health/mirror-health

   1 #! /usr/bin/python3
   2
   3 import os
   4 import requests
   5 import time
   6 import calendar
   7 import logging
   8 from email.utils import parsedate
   9 logging.basicConfig(level=logging.INFO)
  10
  11 HOSTS = os.environ['MIRROR_CHECK_HOSTS'].split()
  12 OUTPUT_DIR = "/run/dsa-mirror-health-{}".format(os.environ['MIRROR_CHECK_SERVICE'])
  13 HEALTH_FILE = os.path.join(OUTPUT_DIR, "health")
  14 URL = os.environ['MIRROR_CHECK_URL']
  15 INTERVAL = int(os.environ.get('MIRROR_CHECK_INTERVAL', '60'))
  16
  17 latest_ts = 0
  18
  19 def retrieve_from_host(host, url):
  20     proxies = {
  21         'http': 'http://{}:80'.format(host),
  22         'https': 'http://{}:443'.format(host),
  23     }
  24     return requests.get(url, timeout=5, proxies=proxies, allow_redirects=False)
  25
  26 def last_modified(response):
  27     lm = 0
  28     if response.status_code == 200 and response.headers.get('last-modified'):
  29         lm = calendar.timegm(parsedate(response.headers['last-modified']))
  30     return lm
  31
  32 while True:
  33     start = time.time()
  34     for host in HOSTS:
  35         lm = last_modified(retrieve_from_host(host, URL))
  36         logging.debug("lm for host %s: %s", host, lm)
  37         if lm > latest_ts:
  38             latest_ts = lm
  39     local_lm = last_modified(retrieve_from_host('localhost', URL))
  40     logging.debug("lm for localhost: %s", local_lm)
  41     if local_lm < latest_ts:
  42         try:
  43             logging.info("considering myself unhealthy my ts=%s latest_ts=%s", local_lm, latest_ts)
  44             os.remove(HEALTH_FILE)
  45         except OSError:
  46             pass
  47     else:
  48         logging.info("considering myself healthy")
  49         open(HEALTH_FILE, 'w').write("OK")
  50     sleep_time = start + INTERVAL - time.time()
  51     logging.debug("sleeping for %d seconds", sleep_time)
  52     time.sleep(sleep_time)